[linux-block.git] / fs / gfs2 / ops_export.c

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <asm/semaphore.h>

#include "gfs2.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "ops_export.h"
#include "rgrp.h"

static struct dentry *gfs2_decode_fh(struct super_block *sb,
				     __u32 *fh,
				     int fh_len,
				     int fh_type,
				     int (*acceptable)(void *context,
						       struct dentry *dentry),
				     void *context)
{
	struct gfs2_inum this, parent;

	if (fh_type != fh_len)
		return NULL;

	memset(&parent, 0, sizeof(struct gfs2_inum));

	switch (fh_type) {
	case 8:
		parent.no_formal_ino = ((uint64_t)be32_to_cpu(fh[4])) << 32;
		parent.no_formal_ino |= be32_to_cpu(fh[5]);
		parent.no_addr = ((uint64_t)be32_to_cpu(fh[6])) << 32;
		parent.no_addr |= be32_to_cpu(fh[7]);
	case 4:
		this.no_formal_ino = ((uint64_t)be32_to_cpu(fh[0])) << 32;
		this.no_formal_ino |= be32_to_cpu(fh[1]);
		this.no_addr = ((uint64_t)be32_to_cpu(fh[2])) << 32;
		this.no_addr |= be32_to_cpu(fh[3]);
		break;
	default:
		return NULL;
	}

	return gfs2_export_ops.find_exported_dentry(sb, &this, &parent,
						    acceptable, context);
}

static int gfs2_encode_fh(struct dentry *dentry, __u32 *fh, int *len,
			  int connectable)
{
	struct inode *inode = dentry->d_inode;
	struct gfs2_inode *ip = get_v2ip(inode);
	struct gfs2_sbd *sdp = ip->i_sbd;

	if (*len < 4 || (connectable && *len < 8))
		return 255;

	fh[0] = ip->i_num.no_formal_ino >> 32;
	fh[0] = cpu_to_be32(fh[0]);
	fh[1] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
	fh[1] = cpu_to_be32(fh[1]);
	fh[2] = ip->i_num.no_addr >> 32;
	fh[2] = cpu_to_be32(fh[2]);
	fh[3] = ip->i_num.no_addr & 0xFFFFFFFF;
	fh[3] = cpu_to_be32(fh[3]);
	*len = 4;

	if (!connectable || ip == get_v2ip(sdp->sd_root_dir))
		return *len;

	spin_lock(&dentry->d_lock);
	inode = dentry->d_parent->d_inode;
	ip = get_v2ip(inode);
	gfs2_inode_hold(ip);
	spin_unlock(&dentry->d_lock);

	fh[4] = ip->i_num.no_formal_ino >> 32;
	fh[4] = cpu_to_be32(fh[4]);
	fh[5] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
	fh[5] = cpu_to_be32(fh[5]);
	fh[6] = ip->i_num.no_addr >> 32;
	fh[6] = cpu_to_be32(fh[6]);
	fh[7] = ip->i_num.no_addr & 0xFFFFFFFF;
	fh[7] = cpu_to_be32(fh[7]);
	*len = 8;

	gfs2_inode_put(ip);

	return *len;
}

struct get_name_filldir {
	struct gfs2_inum inum;
	char *name;
};

static int get_name_filldir(void *opaque, const char *name, unsigned int length,
			    uint64_t offset, struct gfs2_inum *inum,
			    unsigned int type)
{
	struct get_name_filldir *gnfd = (struct get_name_filldir *)opaque;

	if (!gfs2_inum_equal(inum, &gnfd->inum))
		return 0;

	memcpy(gnfd->name, name, length);
	gnfd->name[length] = 0;

	return 1;
}

static int gfs2_get_name(struct dentry *parent, char *name,
			 struct dentry *child)
{
	struct inode *dir = parent->d_inode;
	struct inode *inode = child->d_inode;
	struct gfs2_inode *dip, *ip;
	struct get_name_filldir gnfd;
	struct gfs2_holder gh;
	uint64_t offset = 0;
	int error;

	if (!dir)
		return -EINVAL;

	if (!S_ISDIR(dir->i_mode) || !inode)
		return -EINVAL;

	dip = get_v2ip(dir);
	ip = get_v2ip(inode);

	*name = 0;
	gnfd.inum = ip->i_num;
	gnfd.name = name;

	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	if (error)
		return error;

	error = gfs2_dir_read(dip, &offset, &gnfd, get_name_filldir);

	gfs2_glock_dq_uninit(&gh);

	if (!error && !*name)
		error = -ENOENT;

	return error;
}

static struct dentry *gfs2_get_parent(struct dentry *child)
{
	struct qstr dotdot = { .name = "..", .len = 2 };
	struct inode *inode;
	struct dentry *dentry;
	int error;

	error = gfs2_lookupi(child->d_inode, &dotdot, 1, &inode);
	if (error)
		return ERR_PTR(error);

	dentry = d_alloc_anon(inode);
	if (!dentry) {
		iput(inode);
		return ERR_PTR(-ENOMEM);
	}

	return dentry;
}

static struct dentry *gfs2_get_dentry(struct super_block *sb, void *inum_p)
{
	struct gfs2_sbd *sdp = get_v2sdp(sb);
	struct gfs2_inum *inum = (struct gfs2_inum *)inum_p;
	struct gfs2_holder i_gh, ri_gh, rgd_gh;
	struct gfs2_rgrpd *rgd;
	struct gfs2_inode *ip;
	struct inode *inode;
	struct dentry *dentry;
	int error;

	/* System files? */

	inode = gfs2_iget(sb, inum);
	if (inode) {
		ip = get_v2ip(inode);
		if (ip->i_num.no_formal_ino != inum->no_formal_ino) {
			iput(inode);
			return ERR_PTR(-ESTALE);
		}
		goto out_inode;
	}

	error = gfs2_glock_nq_num(sdp,
				  inum->no_addr, &gfs2_inode_glops,
				  LM_ST_SHARED, LM_FLAG_ANY | GL_LOCAL_EXCL,
				  &i_gh);
	if (error)
		return ERR_PTR(error);

	error = gfs2_inode_get(i_gh.gh_gl, inum, NO_CREATE, &ip);
	if (error)
		goto fail;
	if (ip)
		goto out_ip;

	error = gfs2_rindex_hold(sdp, &ri_gh);
	if (error)
		goto fail;

	error = -EINVAL;
	rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
	if (!rgd)
		goto fail_rindex;

	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	if (error)
		goto fail_rindex;

	error = -ESTALE;
	if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
		goto fail_rgd;

	gfs2_glock_dq_uninit(&rgd_gh);
	gfs2_glock_dq_uninit(&ri_gh);

	error = gfs2_inode_get(i_gh.gh_gl, inum, CREATE, &ip);
	if (error)
		goto fail;

	error = gfs2_inode_refresh(ip);
	if (error) {
		gfs2_inode_put(ip);
		goto fail;
	}

 out_ip:
	error = -EIO;
	if (ip->i_di.di_flags & GFS2_DIF_SYSTEM) {
		gfs2_inode_put(ip);
		goto fail;
	}

	gfs2_glock_dq_uninit(&i_gh);

	inode = gfs2_ip2v(ip);
	gfs2_inode_put(ip);

	if (!inode)
		return ERR_PTR(-ENOMEM);

 out_inode:
	dentry = d_alloc_anon(inode);
	if (!dentry) {
		iput(inode);
		return ERR_PTR(-ENOMEM);
	}

	return dentry;

 fail_rgd:
	gfs2_glock_dq_uninit(&rgd_gh);

 fail_rindex:
	gfs2_glock_dq_uninit(&ri_gh);

 fail:
	gfs2_glock_dq_uninit(&i_gh);
	return ERR_PTR(error);
}

struct export_operations gfs2_export_ops = {
	.decode_fh = gfs2_decode_fh,
	.encode_fh = gfs2_encode_fh,
	.get_name = gfs2_get_name,
	.get_parent = gfs2_get_parent,
	.get_dentry = gfs2_get_dentry,
};
Commit	Line	Data
b3b94faa DT	1	/*
	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
	3	* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
	4	*
	5	* This copyrighted material is made available to anyone wishing to use,
	6	* modify, copy, or redistribute it subject to the terms and conditions
	7	* of the GNU General Public License v.2.
	8	*/
	9
	10	#include <linux/sched.h>
	11	#include <linux/slab.h>
	12	#include <linux/spinlock.h>
	13	#include <linux/completion.h>
	14	#include <linux/buffer_head.h>
	15	#include <asm/semaphore.h>
	16
	17	#include "gfs2.h"
	18	#include "dir.h"
	19	#include "glock.h"
	20	#include "glops.h"
	21	#include "inode.h"
	22	#include "ops_export.h"
	23	#include "rgrp.h"
	24
	25	static struct dentry gfs2_decode_fh(struct super_block sb,
	26	__u32 *fh,
	27	int fh_len,
	28	int fh_type,
	29	int (acceptable)(void context,
	30	struct dentry *dentry),
	31	void *context)
	32	{
	33	struct gfs2_inum this, parent;
	34
b3b94faa DT	35	if (fh_type != fh_len)
	36	return NULL;
	37
	38	memset(&parent, 0, sizeof(struct gfs2_inum));
	39
	40	switch (fh_type) {
	41	case 8:
	42	parent.no_formal_ino = ((uint64_t)be32_to_cpu(fh[4])) << 32;
	43	parent.no_formal_ino \|= be32_to_cpu(fh[5]);
	44	parent.no_addr = ((uint64_t)be32_to_cpu(fh[6])) << 32;
	45	parent.no_addr \|= be32_to_cpu(fh[7]);
	46	case 4:
	47	this.no_formal_ino = ((uint64_t)be32_to_cpu(fh[0])) << 32;
	48	this.no_formal_ino \|= be32_to_cpu(fh[1]);
	49	this.no_addr = ((uint64_t)be32_to_cpu(fh[2])) << 32;
	50	this.no_addr \|= be32_to_cpu(fh[3]);
	51	break;
	52	default:
	53	return NULL;
	54	}
	55
	56	return gfs2_export_ops.find_exported_dentry(sb, &this, &parent,
	57	acceptable, context);
	58	}
	59
	60	static int gfs2_encode_fh(struct dentry dentry, __u32 fh, int *len,
	61	int connectable)
	62	{
	63	struct inode *inode = dentry->d_inode;
	64	struct gfs2_inode *ip = get_v2ip(inode);
	65	struct gfs2_sbd *sdp = ip->i_sbd;
	66
b3b94faa DT	67	if (len < 4 \|\| (connectable && len < 8))
	68	return 255;
	69
	70	fh[0] = ip->i_num.no_formal_ino >> 32;
	71	fh[0] = cpu_to_be32(fh[0]);
	72	fh[1] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
	73	fh[1] = cpu_to_be32(fh[1]);
	74	fh[2] = ip->i_num.no_addr >> 32;
	75	fh[2] = cpu_to_be32(fh[2]);
	76	fh[3] = ip->i_num.no_addr & 0xFFFFFFFF;
	77	fh[3] = cpu_to_be32(fh[3]);
	78	*len = 4;
	79
f42faf4f	80	if (!connectable \|\| ip == get_v2ip(sdp->sd_root_dir))
b3b94faa DT	81	return *len;
	82
	83	spin_lock(&dentry->d_lock);
	84	inode = dentry->d_parent->d_inode;
	85	ip = get_v2ip(inode);
	86	gfs2_inode_hold(ip);
	87	spin_unlock(&dentry->d_lock);
	88
	89	fh[4] = ip->i_num.no_formal_ino >> 32;
	90	fh[4] = cpu_to_be32(fh[4]);
	91	fh[5] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
	92	fh[5] = cpu_to_be32(fh[5]);
	93	fh[6] = ip->i_num.no_addr >> 32;
	94	fh[6] = cpu_to_be32(fh[6]);
	95	fh[7] = ip->i_num.no_addr & 0xFFFFFFFF;
	96	fh[7] = cpu_to_be32(fh[7]);
	97	*len = 8;
	98
	99	gfs2_inode_put(ip);
	100
	101	return *len;
	102	}
	103
	104	struct get_name_filldir {
	105	struct gfs2_inum inum;
	106	char *name;
	107	};
	108
	109	static int get_name_filldir(void opaque, const char name, unsigned int length,
	110	uint64_t offset, struct gfs2_inum *inum,
	111	unsigned int type)
	112	{
	113	struct get_name_filldir gnfd = (struct get_name_filldir )opaque;
	114
	115	if (!gfs2_inum_equal(inum, &gnfd->inum))
	116	return 0;
	117
	118	memcpy(gnfd->name, name, length);
	119	gnfd->name[length] = 0;
	120
	121	return 1;
	122	}
	123
	124	static int gfs2_get_name(struct dentry parent, char name,
	125	struct dentry *child)
	126	{
	127	struct inode *dir = parent->d_inode;
	128	struct inode *inode = child->d_inode;
	129	struct gfs2_inode dip, ip;
	130	struct get_name_filldir gnfd;
	131	struct gfs2_holder gh;
	132	uint64_t offset = 0;
	133	int error;
	134
	135	if (!dir)
	136	return -EINVAL;
	137
b3b94faa DT	138	if (!S_ISDIR(dir->i_mode) \|\| !inode)
	139	return -EINVAL;
	140
	141	dip = get_v2ip(dir);
	142	ip = get_v2ip(inode);
	143
	144	*name = 0;
	145	gnfd.inum = ip->i_num;
	146	gnfd.name = name;
	147
	148	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	149	if (error)
	150	return error;
	151
	152	error = gfs2_dir_read(dip, &offset, &gnfd, get_name_filldir);
	153
	154	gfs2_glock_dq_uninit(&gh);
	155
	156	if (!error && !*name)
	157	error = -ENOENT;
	158
	159	return error;
	160	}
	161
	162	static struct dentry gfs2_get_parent(struct dentry child)
	163	{
b3b94faa	164	struct qstr dotdot = { .name = "..", .len = 2 };
b3b94faa DT	165	struct inode *inode;
	166	struct dentry *dentry;
	167	int error;
	168
7359a19c	169	error = gfs2_lookupi(child->d_inode, &dotdot, 1, &inode);
b3b94faa DT	170	if (error)
	171	return ERR_PTR(error);
	172
b3b94faa DT	173	dentry = d_alloc_anon(inode);
	174	if (!dentry) {
	175	iput(inode);
	176	return ERR_PTR(-ENOMEM);
	177	}
	178
	179	return dentry;
	180	}
	181
	182	static struct dentry gfs2_get_dentry(struct super_block sb, void *inum_p)
	183	{
	184	struct gfs2_sbd *sdp = get_v2sdp(sb);
	185	struct gfs2_inum inum = (struct gfs2_inum )inum_p;
	186	struct gfs2_holder i_gh, ri_gh, rgd_gh;
	187	struct gfs2_rgrpd *rgd;
	188	struct gfs2_inode *ip;
	189	struct inode *inode;
	190	struct dentry *dentry;
	191	int error;
	192
b3b94faa DT	193	/* System files? */
	194
	195	inode = gfs2_iget(sb, inum);
	196	if (inode) {
	197	ip = get_v2ip(inode);
	198	if (ip->i_num.no_formal_ino != inum->no_formal_ino) {
	199	iput(inode);
	200	return ERR_PTR(-ESTALE);
	201	}
	202	goto out_inode;
	203	}
	204
	205	error = gfs2_glock_nq_num(sdp,
	206	inum->no_addr, &gfs2_inode_glops,
	207	LM_ST_SHARED, LM_FLAG_ANY \| GL_LOCAL_EXCL,
	208	&i_gh);
	209	if (error)
	210	return ERR_PTR(error);
	211
	212	error = gfs2_inode_get(i_gh.gh_gl, inum, NO_CREATE, &ip);
	213	if (error)
	214	goto fail;
	215	if (ip)
	216	goto out_ip;
	217
	218	error = gfs2_rindex_hold(sdp, &ri_gh);
	219	if (error)
	220	goto fail;
	221
	222	error = -EINVAL;
	223	rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
	224	if (!rgd)
	225	goto fail_rindex;
	226
	227	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	228	if (error)
	229	goto fail_rindex;
	230
	231	error = -ESTALE;
	232	if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
	233	goto fail_rgd;
	234
	235	gfs2_glock_dq_uninit(&rgd_gh);
	236	gfs2_glock_dq_uninit(&ri_gh);
	237
	238	error = gfs2_inode_get(i_gh.gh_gl, inum, CREATE, &ip);
	239	if (error)
	240	goto fail;
	241
	242	error = gfs2_inode_refresh(ip);
	243	if (error) {
	244	gfs2_inode_put(ip);
	245	goto fail;
	246	}
	247
b3b94faa DT	248	out_ip:
	249	error = -EIO;
	250	if (ip->i_di.di_flags & GFS2_DIF_SYSTEM) {
	251	gfs2_inode_put(ip);
	252	goto fail;
	253	}
	254
	255	gfs2_glock_dq_uninit(&i_gh);
	256
	257	inode = gfs2_ip2v(ip);
	258	gfs2_inode_put(ip);
	259
	260	if (!inode)
	261	return ERR_PTR(-ENOMEM);
	262
	263	out_inode:
	264	dentry = d_alloc_anon(inode);
	265	if (!dentry) {
	266	iput(inode);
	267	return ERR_PTR(-ENOMEM);
	268	}
	269
	270	return dentry;
	271
	272	fail_rgd:
	273	gfs2_glock_dq_uninit(&rgd_gh);
	274
	275	fail_rindex:
	276	gfs2_glock_dq_uninit(&ri_gh);
	277
	278	fail:
	279	gfs2_glock_dq_uninit(&i_gh);
	280	return ERR_PTR(error);
	281	}
	282
	283	struct export_operations gfs2_export_ops = {
	284	.decode_fh = gfs2_decode_fh,
	285	.encode_fh = gfs2_encode_fh,
	286	.get_name = gfs2_get_name,
	287	.get_parent = gfs2_get_parent,
	288	.get_dentry = gfs2_get_dentry,
	289	};
	290